What’s next?

City Council certifies vote the week of May 7, after which San Diego City Attorney’s office will file a lawsuit to test the legality of the hotel tax.

An environmental impact report for the expansion project will be brought to San Diego port commissioners by late summer.

Project goes before the California Coastal Commission, possibly in the fall.

Construction starts as early as late this year.

New hotel tax could possibly start being collected by January of 2013.

Expanded center opens, at the earliest, by late 2016.

Plans to expand the San Diego Convention Center took a major leap forward Tuesday, with the approval of a new room tax by local hoteliers.

Expected to generate more than $30 million a year, the tax increase is key to financing the bulk of the $520 million expansion. It could start being collected as early as January of next year, although the start date could be much later than that, according to Mayor Jerry Sanders' office.

The city's hotel owners voted on the room surcharge through a mail-in ballot process, which began last month. The deadline for submitting ballots was 8 p.m. Monday. Of the votes cast -- which were weighted by the size of the hotels and the revenues they generate -- more than 92 percent were in favor of the tax.

City leaders have long argued that San Diego is missing out on hundreds of millions of dollars in visitor spending because the waterfront center cannot accommodate the much larger conventions that now seek out more spacious centers.

Significant hurdles, though, remain before workers can dig the first shovelfuls of dirt on the expansion site. The San Diego City Attorney's office plans in early May to file a "validation" lawsuit to confirm whether the taxing plan is in fact legal. It could potentially take as long as a year or even longer to secure a ruling from a judge, said Jonathan Heller, spokesman for San Diego City Attorney Jan Goldsmith.

Also required before the project can move forward is approval from the California Coastal Commission. Leaders of organized labor in San Diego, who continue to oppose the taxing plan for the expansion, have promised a fight at the hearing.

Once the room surcharge goes into effect, guests at hotels closest to the convention center would have to pay an additional 3 percent on their room bills; those staying in Mission Valley and Mission Bay and around Lindbergh Field, 2 percent; and the rest of the city, 1 percent. Hotel guests currently pay a total room tax of 12.5 percent.

Sanders, who has been spearheading the effort to expand the center, touted its benefits, including the 11,000 temporary and permanent jobs it's expected to create.

"Not only will this expansion help us keep the conventions we have now from leaving for other cities with larger centers, it will help us attract the next, larger tier of conventions," Sanders said during a news conference to celebrate the hotelier vote.

Revenue generated by the new levy would help cover up to $575 million in 30-year bonds for the center's expansion. The Port of San Diego is contributing $3 million a year over 20 years, and the city is being asked to cover $3.5 million annually over 30 years.

The city's largest convention, Comic-Con, has agreed to remain in San Diego through 2015 but has made it clear it may have to look elsewhere if the center is not expanded.

Although the hotel industry has presented a united front in favor of the expansion, some hotel owners with properties located farther away have said the taxing structure was unfair because they benefit so little from most conventions.

"Although during certain conventions, we see some residual impact, that impact is limited to only two or three conventions a year," said Terry Underwood, general manager of the Grande Colonial La Jolla.

"My concern is that between this tax (and other San Diego hotel taxes), we're getting to be an expensive tax city, and that's not a good reputation for a city to have."

Also critical of the taxing plan are local labor leaders, who have said the new surcharge should have been put to a vote of the people. They also assert that the project will yield mostly low-paying jobs.

"What we want are protections for workers, union and non-union so that going into the future the workers will be from our local communities and that they'll be paid a living wage with health benefits," said Lorena Gonzalez, Secretary-Treasurer of the San Diego-Imperial Counties Labor Council. "We can't allow this to move forward and create a bunch of poverty-wage jobs."